Ultrasonographically assessed maximum carotid artery wall thickness in Mexico City residents and Mexican Americans living in San Antonio, Texas. Association with diabetes and cardiovascular risk factors

Measurements of carotid artery wall thickness are often used as a surrogate for atherosclerosis. However, few studies have performed these measurements in populations of Mexican origin. Since Mexicans in Mexico City consume high-carbohydrate diets and have carbohydrate-induced dyslipidemia (high triglyceride and low HDL cholesterol levels) compared with Mexican Americans living in San Antonio, Tex, we questioned whether they also had more atherosclerosis than San Antonio Mexican Americans. Mean maximum intimal-medial thickness (IMT) of the common (CCA) and internal (ICA) carotid arteries were measured in 867 subjects aged 35 to 64 years (40% men) in two Mexican-origin populations, one from San Antonio (n = 202) and the other from Mexico City (n = 665). IMT's in the two cities were compared, and their associations with cardiovascular risk factors were analyzed. Older age, male sex, high levels of total cholesterol, low levels of HDL cholesterol, and high systolic blood pressure were positively associated with both CCA IMT and ICA IMT. Cigarette smoking was significantly associated with ICA IMT. CCA and ICA IMTs in diabetic subjects were thicker than in nondiabetic subjects in both men and women (all P < = .05). CCA IMT was thicker in the San Antonio than the Mexico City subjects after adjustment for cardiovascular risk factors (0.81 versus 0.76 mm in men and 0.77 versus 0.71 mm in women; P < .001 for city difference). San Antonio men also had thicker ICA IMT than their counterparts in Mexico City (0.88 versus 0.83 mm), but the reverse was true for women (0.73 versus 0.77 mm; interaction between sex and city, P < .05). Our results indicate that men had higher carotid IMTs than women. CCA IMT was thicker in San Antonio Mexican Americans than in Mexico City residents. The differences in ICA IMTs between San Antonio and Mexico City were inconsistent. Thus, since Mexico City residents consume high-carbohydrate diets, the data do not support an atherogenic effect of such diets. The interaction between sex and city on ICA IMT deserves further study.     

Genetic basis of variation in carotid artery wall thickness

BACKGROUND AND PURPOSE: Other than the documented associations of risk factors and carotid artery wall thickness, the genetic basis of variation in carotid artery intimal-medial thickness (IMT) is unknown. The purpose of this study was to examine the extent to which variation in common carotid artery (CCA) IMT and internal carotid artery (ICA) IMT are under genetic control. METHODS: The sibship data used for this analysis were part of an epidemiological survey in Mexico City. The CCA and ICA analyses were based on 46 and 44 sibships of various sizes, respectively. The CCA and ICA IMTs were measured with carotid ultrasonography. Using a robust variance decomposition method, we performed genetic analyses of CCA IMT and ICA IMT measurements with models incorporating several cardiovascular risk factors (eg, lipids, diabetes, blood pressure, and smoking) as covariates. RESULTS: After accounting for the effects of covariates, we detected high heritabilities for CCA IMT (h2 = 0.92 +/- 0.05, P = .001) and ICA IMT (h2 = 0.86 +/- 0.13, P = .029). Genes accounted for 66.0% of the total variation in CCA IMT, whereas 27.7% of variation was attributable to covariates. For ICA IMT, genes explained a high proportion (74.9%) of total phenotypic variation. The covariates accounted for 11.5% of variation in ICA IMT. CONCLUSIONS: Our results suggest that substantial proportions of phenotypic variance in CCA IMT and ICA IMT are attributable to shared genetic factors.     

Carotid and femoral artery wall thickness and stiffness in patients at risk for cardiovascular disease, with special emphasis on hyperhomocysteinemia

Recent developments in ultrasound technology enable the noninvasive measurement of structural and functional vessel wall changes. Until now, the effect of homocysteine on the arterial wall has remained unclear: reports on intima-media thickness (IMT) yield conflicting results, whereas data on vessel wall stiffness are lacking. Because several cardiovascular risk factors result in an increased IMT or stiffness, different groups at risk for atherosclerotic disease, with special emphasis on hyperhomocysteinemia, were studied. Nineteen patients homozygous and 14 subjects heterozygous for cystathionine beta-synthase (CBS) deficiency, 21 patients with familial hypercholesterolemia (FH), 15 patients with essential hypertension, 20 smokers, and 28 control subjects were studied. The IMT values (both right and left) of the common carotid artery (CCA), bulb (BUL), internal carotid artery (ICA), and common femoral artery (CFA) were measured in millimeters by high-resolution ultrasound (Biosound). The distensibility (DC, in 10(-3). kPa-1) and compliance (CC in mm2. kPa-1) coefficients of the CCA (right and left) and CFA (right) were determined by a wall track system (Pie Medical). The mean IMT of the posterior wall in the CCA was 0.70+/-0.09 mm in healthy controls. For patients with vascular disease, FH, and hypertension and in smokers, the mean CCA IMT was larger, whereas no major differences in IMT were observed in patients either homozygous or heterozygous for CBS deficiency. The DC and CC in the right CCA were 23.5+/-6.9 (10(-3). kPa-1) and 0.9+/-0.3 (mm2. kPa-1) in healthy subjects, slightly lower in patients homozygous for CBS deficiency, and clearly lower in patients with vascular disease, FH, and hypertension. No positive correlation was found between plasma homocysteine level and either IMT, CC, or DC. Because smoking was a confounder in each risk group, a stepwise regression analysis was carried out to assess the contribution of each risk factor on IMT and arterial wall stiffness. Age explained most of the variation in IMT of the CCA (coefficient of determination R2 of 0.34), whereas R2 values for serum low density lipoprotein cholesterol, smoking (pack-years), and systolic blood pressure were 0.08, 0.07, and 0.06, respectively. Homocysteine did not contribute to variation in IMT in both the CCA and CFA. Age and smoking contributed to the variation in IMT in the CFA. The variation in DC and CC in the right CCA and right CFA could in part be explained by age, low density lipoprotein cholesterol, and blood pressure. Plasma homocysteine concentration explained only a small proportion of the variation in DC in the CCA (R2=0.02) and in CC in the CFA (R2=0.04). In this study, no relationship was found between homocysteine level and the thickness of the arterial wall, with only a marginal influence on stiffness.     

Vascular and cardiac remodeling in world class professional cyclists

BACKGROUND: Numerous studies have demonstrated that left ventricular (LV) hypertrophy is often associated with conditioning. METHODS AND RESULTS: The aim of the study was to evaluate cardiac and carotid artery changes induced by professional cycling. We collected M-mode left ventricle and B-mode right common carotid artery data from 149 male professional cyclists before the 1995 "Tour de France" race and 52 male control subjects. LV mass indexed to body surface area in cyclists was double that in control subjects, with no overlap of 95% confidence intervals (cyclists 100.9 to 187 g/m2 and control subjects 51.8 to 96.3 g/m2). Both mean arterial diameter and mean arterial diastolic intima-media thickness (IMT) were 13% higher in cyclists than in control subjects, with overlap of 95% confidence intervals (for arterial IMT 0.45 to 0.65 mm in cyclists and 0.38 to 0.60 mm in control subjects). CONCLUSIONS: Our results suggest that intense cycling has an effect on the cardiovascular system, more pronounced on the left ventricle and less pronounced on large arteries. Nevertheless, athletic training should be considered as a potential determinant of carotid modification.     

Isolation-stress-induced facilitation of passive avoidance memory in the day-old chick

Left ventricular (LV) midwall shortening (MWS) is subnormal in relation to LV circumferential end-systolic stress (ESS) (ESS-corrected MWS) in many hypertensive patients with normal LV chamber function and predicts subsequent morbidity and mortality. However, little is known of the relations of LV midwall function to demographic and metabolic variables or to arterial geometry. Asymptomatic, unmedicated normotensive (n=366) or hypertensive (n=282) adults were assessed with echocardiography and carotid ultrasound. In normal adults, lower LV MWS and ESS-corrected MWS, an index of LV contractility, were related independently to high total peripheral resistance, high heart rate, and male gender (all P<.00001), lower serum HDL cholesterol (P=.001) and diastolic pressure (P=.003), and for ESS-corrected MWS only, arterial relative wall thickness (RWT, P=.03). Among hypertensive patients, lower values for both midwall function indices were associated independently with higher peripheral resistance (P<.00001), heart rate (P<.00005), body mass index (P<.01), and arterial RWT (P=.04), as well as male gender (P<.0002). In the entire population, lower LV MWS was independently related to higher peripheral resistance, heart rate (both P<.00001), body mass index (P=.0006) and arterial RWT (P=.009); male gender (P<.00001); and lower age (P=.004), diastolic pressure (P=.042), and systolic carotid artery expansion (P=.032). Lower ESS-corrected MWS in the entire population was independently associated with higher peripheral resistance and heart rate (both P<.00001), body mass index (P=.0006), arterial RWT (P=.004); male gender; and lower diastolic pressure (both P<.00001), age (P<.00005), arterial expansion in systole (P=.006), and serum HDL cholesterol levels (P=.04). Among a subset (n=60), ESS-corrected MWS was positively related to apolipoprotein A1 (P=.004) and negatively to hemoglobin A1c (P<.01). Thus, higher LV midwall function is associated with female gender and more favorable profiles of hemodynamics, metabolic pattern, and arterial structure and function.     

Increased common carotid intima-media thickness. Adaptive response or a reflection of atherosclerosis? Findings from the Rotterdam Study

BACKGROUND AND PURPOSE: Carotid intima-media thickness (IMT) measurements are used widely to study atherosclerosis. Some have suggested that an increased IMT reflects a nonatherosclerotic adaptive response to changes in shear stress and tensile stress. This stems from the hypothesis that changes in shear stress and subsequently in lumen diameter are followed by changes in IMT to keep tensile stress constant. We studied the relation of common carotid IMT to common carotid end-diastolic lumen diameter and tensile stress, as approximated by mean arterial pressure (lumen diameter/IMT)]. METHODS: A cross-sectional analysis was performed with data obtained from the first 1715 participants in the Rotterdam Study, a population-based cohort study among 7983 subjects aged 55 years and over who underwent ultrasonographic examination of the carotid arteries. End-diastolic lumen diameter and IMT of the common carotid arteries were evaluated and quantified. RESULTS: With increasing IMT, inner and outer lumen diameters increased gradually, and beyond an IMT of 1.10 mm, the inner lumen diameter decreased. Tensile stress increased with increasing lumen diameter instead of being constant. The lumen-to-IMT ratio was constant across levels of mean arterial pressure. CONCLUSIONS: Our findings are compatible with the view that at lower degrees of IMT, the thickening appears to reflect an equilibrium state in which the effects of pressure and flow on the arteries are in balance, given a characteristic relation between shear stress and local transmural pressure. Beyond a certain level, IMT more likely may represent atherosclerosis. Regardless of whether common carotid IMT reflects local atherosclerosis, it may still serve as a graded marker for cardiovascular risk.     

Repeat consultations in pediatric hospital emergencies

OBJECTIVE: To assess the extent of early atherosclerotic changes of the carotid arteries in young patients with familial hypercholesterolaemia (FH) detected as increased intima-media thickness (IMT), and to determine the relations between IMT and some clinical and blood variables such as lipid and lipoprotein(a) (Lp(a)) concentration and haemostatic factors. DESIGN: The IMT of the carotid bifurcation, the proximal 1 cm of the internal carotid artery, and the distal 1 cm of the common carotid artery was determined in all subjects using B mode ultrasonography. Blood lipids, fasting glucose, and several haemostatic variables were also analysed. SUBJECTS: 28 patients with FH (12 males and 16 females aged 11 to 27 years, one homozygote, 27 heterozygotes) and 28 sex and age matched normolipidaemic healthy subjects. RESULTS: The mean carotid IMT (the average of six measurements of the maximum far wall IMT in the three carotid segments on each side) was significantly greater in patients with FH than in controls (mean (SD) 0.71 (0.15) v 0.49 (0.08) mm, P < 0.001). In all subjects, the mean IMT was significantly correlated with total cholesterol (r = 0.59), low density lipoprotein (LDL) cholesterol (r = 0.60), triglycerides (r = 0.27), and systolic blood pressure (r = 0.47). No correlation was found between the mean IMT and Lp(a), fibrinogen, tissue plasminogen activator, and plasminogen activator inhibitor 1. CONCLUSIONS: The majority of young patients with FH have a greater intima-media thickness of the carotid arteries than healthy subjects. Since the individual susceptibility of patients with FH to increased LDL cholesterol is different, B mode ultrasonography could provide a useful tool to identify those who are more likely to develop premature atherosclerotic disease.     

Differences in near-wall shear rate in the carotid artery within subjects are associated with different intima-media thicknesses

In the common carotid artery, reflections originating from the periphery and the flow divider may affect the shape of the flow velocity profile and, hence, near-wall shear rate (WSR) differently just before the bifurcation (location B) than 20 to 30 mm farther upstream (location A). Recent developments in ultrasound technology allow the assessment of WSR and intima-media thickness (IMT) at the same site in the carotid artery in vivo. We therefore determined WSR at locations A and B and investigated whether the differences between both sites, if any, were associated with different IMTs and different mechanical properties of the arterial wall. The effect of age on the possible differences was assessed as well. The study was performed on presumably healthy volunteers (n=53). In all individuals, IMT was larger at location B than at location A. The relative difference in IMT between both locations was not affected by age. No significant differences in diameter and distension were found between locations. Near peak systolic and near mean WSR at the posterior wall (PWSRp and MWSRp, respectively) were significantly lower at location B than at location A. The relative differences in PWSRp and MWSRp between both locations within subjects were independent of age. The velocity profiles were more blunted at location A than at location B. PWSRp and MWSRp significantly decreased and IMT significantly increased with age at both locations. IMT was negatively correlated with PWSRP and MWSRP at location B, but this correlation was not significant at location A. In summary, in the common carotid artery, the lower WSR near the bifurcation, as compared with 20 to 30 mm upstream, is associated with a larger IMT than at the more proximal site. The relative difference between both locations within subjects is independent of age.     

Automated intima-media thickness: the Los Angeles Atherosclerosis Study

Common carotid artery (CCA) intima-media thickness (IMT) from B-mode ultrasound is a widely used measure of early atherosclerosis. This study evaluated within- and between-sonographer reproducibility of automated edge-tracking IMT using a low-cost mobile scanner. B-mode images of the left and right CCA were acquired on two occasions (interval of 2-14 days) by two sonographers for 38 subjects, aged 31-75 y. Reproduciblity error was measured as the mean absolute difference (MAD+/-SEM) and the standard deviation of differences (SDdelta) between repeated measurements. Within-sonographer (MAD=0.027+/-0.006 mm; SDdelta=0.044 mm) and between-sonographer errors (MAD=0.041+/-0.008 mm; SDdelta=0.064) in IMT (mean=0.74, SD=0.14) of a single artery were small compared to those of other protocols. Combined averaging across both body positions and arteries reduced intersonographer MAD by 47% (MAD=0.022+/-0.003 mm; SDdelta=0.029 mm). These data demonstrate that the proposed IMT protocol reduces reproducibility error by more than 50% relative to several protocols used in other major studies.     

Regional distribution of 5alpha-reductase type 1 and type 2 mRNA along the human epididymis

BACKGROUND AND PURPOSE: In women, symptoms of coronary artery disease are delayed by 10 to 15 years in comparison with men, most likely because of the protective effect of ovarian hormones. This report compares the prevalence and degree of carotid atherosclerosis between 292 premenopausal women and 294 women at 5 to 8 years after menopause. METHODS: Scans were performed in the same laboratory over the same time period for both groups. Intima-media thickness (IMT) was averaged across the common, bulb, and internal carotids. The plaque index summarized degree of focal plaque based on the size and number of plaques throughout both carotid systems. RESULTS: Mean IMT was 0.69 mm for premenopausal women and 0.77 mm for postmenopausal women (P < 0.001). Prevalence of plaque was 25% among premenopausal women and 54% among postmenopausal women (P < 0.001). In both premenopausal and postmenopausal women, risk factors measured before menopause were associated with carotid atherosclerosis. Premenopausal risk factors independently associated with IMT were higher pulse pressure (P < 0.001), triglycerides (P = 0.002), body mass index (P < 0.001), and study group (a surrogate for both age and menopausal status; P < 0.001). Premenopausal risk factors independently associated with focal plaque were ever smoking (P = 0.002), higher pulse pressure (P = 0.028), higher LDL (P = 0.003), age at baseline (P = 0.050), and study group (P < 0.001). CONCLUSIONS: Subclinical carotid atherosclerosis can be observed in middle-aged women. Risk factors measured before menopause are clearly associated with subclinical disease measured both concurrently and at 5 to 8 years after menopause.     

Relations of intimal-medial thickness among sites within the carotid artery as evaluated by B-mode ultrasound. ARIC Investigators. Atherosclerosis Risk in Communities

BACKGROUND AND PURPOSE: B-mode ultrasound is a widely used technique for the clinical and epidemiological assessment of carotid atherosclerosis. This article describes the relation between arterial intimal-medial thickness (IMT) at different sites within the extracranial carotid artery. METHODS: IMT was measured by B-mode real-time ultrasound as an index of atherosclerotic involvement in the extracranial carotid arteries as part of the population-based Atherosclerosis Risk in Communities (ARIC) study. The relation between IMT at different sites was described by correlation coefficients and percentile regression techniques based on between 4034 and 9386 pairs of measurements (variation in sample size depending on the paired sites). RESULTS: Increased IMT at one site was associated with increased IMT at other sites. The correlation between right and left IMT at the same anatomic location in the carotid artery ranged from .34 to .49; the correlation at different anatomic locations in the carotid artery on the same side ranged from .25 to .43. The distribution of IMT, described by the percentiles of IMT at the inference site as a function of IMT at the index site, showed constricted percentiles of IMT at the inference site for small IMT at the index site and an increase in the spread of percentiles with increasing IMT. CONCLUSIONS: Although increased carotid IMT at one site is positively associated with thickened walls at other carotid sites, the ability to accurately predict wall thickness at a site given the wall thickness at other sites is modest. The general association between sites supports the systemic nature of atherosclerosis, while the lack of tight agreement between sites supports the focal nature of the atherosclerotic process.     

Determination of intima-media thickness of the carotid artery: influences of methods, proband and examination variables

AIM: Comparison of two different methods for the measurement of the common carotid artery intima-media thickness (IMT) regarding results and reproducibility, and investigation of the influence of the subjects' characteristics on the results. METHOD: 20 healthy subjects were studied (6 men, 14 women, mean age 27.4 +/- 4.4 years). B-Mode pictures were taken of the carotid arteries on both sides (longitudinal sections from ventral and lateral) and stored for measurement either in systole or in diastole. Maximum IMT was measured conventionally by manual setting of calipers (method 1), the mean IMT over a length of 1 cm was calculated from the area of the intima plus media by means of a computer (method 2). 10 subjects were studied twice for the evaluation of intra- and interobserver variability. RESULTS: Mean IMT was between 0.48 +/- 0.07 mm (method 1/observer 1) and 0.55 +/- 0.07 mm (method 2/observer 2). IMT values resulting from method 2 had a better correlation in repeated measurements (coefficient 0.84/0.93 for inter-/intraobserver comparison) than those resulting from method 1 (0.79/0.67). Age and height were significantly correlated with IMT (coefficients 0.53 and 0.52 for method 2), no correlation was found for body weight, BMI, sex or years of smoking. There was a significant inverse correlation between blood pressure and IMT (-0.21 to -0.32). CONCLUSION: In younger healthy subjects, the results of IMT measurement are influenced by age, height and actual blood pressure. The values resulting from both methods are comparable, whereas method 2 has a better reproducibility.     

Clinical, haematological and molecular studies in patients with chromosome translocation t(7;11): a study of four Chinese patients in Taiwan

We examined the association between the polymorphism of the apolipoprotein E (apoE) and the ACE genes and the intima-media thickness (IMT) of the carotid and femoral arteries measured using ultrasonography. The values of IMT of each artery were significantly higher in NIDDM patients (n = 356) than in control subjects (n = 235). The E4 allele or the D allele did not affect clinical characteristics, including age, fasting plasma glucose, total cholesterol, HDL cholesterol, LDL cholesterol, or blood pressure, in NIDDM or control subjects. No difference in the carotid IMT value was noted among the apoE genotypes in control or diabetic subjects. The carotid IMT was significantly higher in diabetic patients with the DD genotype (1.200 +/- 0.586 mm) than in those with the II genotypes (0.990 +/- 0.364 mm). Neither the E4 allele nor the D allele affected the femoral IMT in control or diabetic subjects. Multiple regression analysis demonstrated that the carotid IMT of NIDDM patients was associated with age, the D allele, and LDL cholesterol but not with the E4 allele, whereas that of control subjects was associated with age, sex, systolic blood pressure, LDL cholesterol, and HDL cholesterol, inversely. These results suggested that the E4 allele was not associated with the carotid or femoral IMTs, but that the D allele was statistically associated with carotid IMT in NIDDM patients but not control subjects. However, since the association was weak (2.3% explanatory power), its biological significance remains to be determined.     

Proinsulin and insulin concentrations in relation to carotid wall thickness: Insulin Resistance Atherosclerosis Study

BACKGROUND AND PURPOSE: Insulin resistance and hyperinsulinemia have been associated with atherosclerosis. Recent attention has focused on the possible role of proinsulin because most radioimmunoassays for insulin cross-react with proinsulin. Therefore, it is not known which of the two, insulin per se or proinsulin, is more strongly related to atherosclerosis. METHODS: We examined the relation between fasting proinsulin, fasting split proinsulin, fasting and 2-hour insulin (after oral glucose load), and intima-media wall thickness (IMT) in the common carotid artery (CCA) and internal carotid artery (ICA) in 985 nondiabetic subjects from the Insulin Resistance Atherosclerosis Study, a multiethnic study of insulin resistance and atherosclerosis. RESULTS: In the overall population, a weak but significant relation between proinsulin and CCA IMT was observed (r=0.07, P=0.029). However, the relation between proinsulin and IMT was stronger in Hispanics and non-Hispanic whites than in African Americans. In non-Hispanic whites and Hispanics, significant correlations between CCA and proinsulin (r=0.087) and between ICA and proinsulin (r=0.101), split proinsulin (r = 0.092), and fasting insulin (r = 0.087) were observed. The significant correlations became more attenuated (and nonsignificant) after adjustment for cardiovascular risk factors, especially plasminogen activator inhibitor-1 (PAI-1). CONCLUSIONS: The association between proinsulin and IMT, while weak, appears to be stronger than the association between insulin and IMT. Adjustment for PAI-1 markedly attenuated the association between proinsulin and IMT, suggesting a possible mediating role for PAI-1 in this association. It is possible that proinsulin may represent a marker of atherosclerosis rather than a causal factor for atherosclerosis. Studies of the insulin resistance syndrome and atherosclerosis that use insulin as a surrogate for insulin resistance should consider the use of specific insulin assays as well as determination of proinsulin concentrations.     

Left ventricular concentric remodelling and carotid structural changes in essential hypertension

AIM: Left ventricular concentric remodelling defines a modified left ventricular geometry in the presence of a normal left ventricular mass; it is an early and frequent adaptation in arterial hypertension. The present study was designed to evaluate the extent of carotid structural changes in essential hypertensives with left ventricular remodelling. PATIENTS AND METHODS: Two groups of hypertensive patients, who had never previously received anti-hypertensive treatment, 14 with left ventricular concentric remodelling (group I, relative wall thickness 0.48 +/- 0.02) and 48 with normal left ventricular geometry (group II, relative wall thickness 0.37 +/- 0.04) underwent clinical and laboratory examination, echocardiography, carotid artery ultrasonography and 24 h ambulatory blood pressure monitoring (ABPM). The left ventricular dimensions and mass were obtained according to the Penn convention. The intima-media thickness (IMT) of the posterior wall of both common carotid arteries was measured 5, 10 and 20 mm caudally to the bulb and the average value was used for analysis. RESULTS: In both groups age (group I 44 +/- 9 years; group II 40 +/- 9 years), body surface area (group I 1.85 +/- 0.2 m2; group II 1.80 +/- 0.2 m2), duration of hypertension (group I 4.4 +/- 4; group II 3.8 +/- 3.9 years), metabolic parameters and smoking habits were similar. Both clinic and 24 h ABPM values were higher in group I (clinic 157 +/- 12/102 +/- 5; 24 h ABPM 145 +/- 10/95 +/- 7 mmHg) than they were in group II (clinic 146 +/- 11/97 +/- 5; 24 h ABPM = 134 +/- 10/87 +/- 8 mmHg, P < 0.01). The left ventricular mass index (LVMI) and IMT were found to be slightly but significantly greater in group I than they were in group II (LVMI 106 +/- 7 versus 98 +/- 12 g/m2, P < 0.05; IMT 0.68 +/- 0.13 versus 0.61 +/- 0.10 mm, P < 0.05). A significant correlation was found between LVMI and common carotid IMT in the whole group of hypertensive patients (r = 0.43, P < 0.01). CONCLUSIONS: Our results indicate that left ventricular concentric remodelling does not represent the only early cardiovascular change in arterial hypertension but rather is associated often with carotid intima-media thickening.     

Parallel increase in carotid, brachial and left ventricular cross-sectional areas in arterial hypertension

Few data have been published about the relation between the vessels geometry and development of left ventricular (LV) hypertrophy in patients with arterial hypertension. The aim of this study is to describe arterial and LV geometry changes due to mild-to-moderate arterial hypertension in an untreated hypertensive population. In 95 untreated patients with mild-to-moderate hypertension and 23 age- and sex-matched healthy normotensives, we measured the end-diastolic diameter and wall thickness of the left ventricle and the internal diameter and intimal-medial thickness (IMT) of carotid and brachial arteries. From these data, the cross-sectional areas (CSAs) of arterial and myocardial walls were calculated. Hypertensive patients were further subdivided on the basis of the presence of LV hypertrophy defined according to Devereux et al as anatomical LV mass >125 g/m. In hypertensive patients with hypertrophy, carotid and brachial CSAs increased, without significant changes in thickness/diameter ratio (arterial 'enlargement'), while the left ventricle developed 'concentric' hypertrophy. Arterial and LV CSAs showed a significant direct correlation with systolic blood pressure (BP). However, when data were corrected for BP, the correlation between the increase in arterial and LV CSAs became much improved than for the raw data. In conclusion patients with untreated mild-to-moderate hypertension, both carotid and brachial arterial walls showed an enlargement that was proportional to the development of LV hypertrophy. These results suggest that the effects of arterial hypertension on carotid, brachial and LV wall geometry have a common modulation.     

Age-related deterioration in arterial structure and function in postmenopausal women: impact of hormone replacement therapy

Epidemiological evidence suggests that hormone replacement therapy (HRT) reduces morbidity and mortality from cardiovascular diseases in postmenopausal women. In this study, indices of arterial function [total systemic arterial compliance (SAC) and carotid arterial distensibility coefficient (DC)], structure [carotid intima-media thickness (IMT)], and lipid profiles were compared in postmenopausal women on long-term HRT and aged-matched controls. One hundred nine women aged 44 to 77 years taking HRT and an age-matched group of 108 female controls were entered into the study. The two groups were similar for body mass index, smoking status, exercise level, alcohol intake, and blood pressure. Fasting cholesterol, low density lipoprotein, and lipoprotein(a) were reduced and high density lipoprotein increased in the HRT group. IMT increased with age; SAC and DC were reduced with age in both groups. The HRT group had a higher mean SAC (0.42+/-0.02 versus 0.34+/-0.02 U/mm Hg, P=0.0001) and a lower mean IMT (0.67+/-0.01 versus 0.74+/-0.02 mm, P=0.006) than did controls. Subgroup analysis for estrogen versus estrogen plus progestin revealed no differences for SAC and IMT; DC, however, was greater in estrogen-only users. Smokers on HRT had a higher mean SAC (0.41+/-0.02 versus 0.31+/-0.01 U/mm Hg, P=0.008) and a lower IMT (0.65+/-0.02 versus 0.75+/-0.03 mm, P=0.002) than did smokers not taking such therapy. A protective effect of long-term estrogen therapy on age-related changes in arterial structure and function in postmenopausal women was evident in smokers and nonsmokers alike. Progestin appeared to counteract the effects of estrogen on carotid compliance only. Long-term controlled trials are needed to determine the significance of these findings.     

Stress-induced pulse pressure change predicts women's carotid atherosclerosis

BACKGROUND AND PURPOSE: Individuals who exhibit large increases in blood pressure and heart rate during mental stress may be at risk for accelerated atherosclerosis. This report evaluates the association between stress-induced hemodynamic responses and carotid atherosclerosis in 254 healthy postmenopausal women. METHODS: The magnitude of change in blood pressure and heart rate from rest to public speaking and mirror image tracing, two stressful tasks, was measured. Average intima-media thickness (IMT) and focal plaque in the common carotid artery, bulb, and internal carotid artery were measured with the use of duplex ultrasonography on average 2.3 years later. RESULTS: The average IMT was 0.77 mm, with a range of 0.60 to 1.37; 52.5% had at least one plaque. Correlational analysis showed that greater IMT was associated with greater pulse pressure change during mental stress (r = 0.17, P < 0.01). Statistical adjustments for possible confounders (age, hormone replacement therapy use, resting pulse pressure, smoking status, and triglyceride levels) did not alter the results. The plaque index was associated with greater pulse pressure change during the mirror image tracing task (odds ratio = 1.47, P = 0.01) for women with a plaque score of > or = 2 versus 1 or 0, adjusted for possible confounders. CONCLUSIONS: Mental stress-induced pulse pressure changes may influence the development of early atherosclerosis in the carotid artery of women. Widening of pulse pressure during stress, as well as at rest, may be a marker of compromised compliance in the vessel wall.     

Association of hormone replacement therapy and carotid wall thickness in women with and without diabetes

OBJECTIVE: Atherosclerosis is the major underlying cause of death for women with type 2 diabetes. We examined the relationship between use of postmenopausal hormone replacement therapy(HRT) and subclinical atherosclerosis among women with type 2 diabetes, impaired glucose tolerance (IGT), and normal glucose tolerance. RESEARCH DESIGN AND METHODS: A cross-sectional analysis was conducted among 623 postmenopausal women in the Insulin Resistance Atherosclerosis Study (IRAS). Current users of HRT, n = 200, were compared with 104 former users and 319 never users. Intimal-medial wall thicknesses (IMTs) of the common carotid (CCA) and internal carotid (ICA) arteries were used as measures of atherosclerosis. RESULTS: Significant differences between HRT user groups were noted for certain demographic, socioeconomic, and lifestyle factors. After adjustment for these and other coronary heart disease risk factors, current users had a 69 microm thinner ICA IMT than never users (P = 0.06). Former users had a 96 pm thinner ICA IMT than never users (P = 0.03). No significant difference was observed for the CCA. Although women with type 2 diabetes had thicker carotid IMT than women without diabetes, the association between HRT use and thinner IMT was similar in both groups. The difference between current and never users was attenuated by adjustment for HDL and LDL cholesterol. Neither duration of HRT use nor HRT regimen was associated with IMT in either artery. CONCLUSIONS: This analysis suggests that current and former use of HRT is associated with reduced atherosclerosis and that women with type 2 diabetes may receive the same benefit from HRI as women without diabetes.     

Carotid atherosclerosis in adolescents and young adults with IDDM. Relation to urinary endothelin, albumin, free cortisol, and other factors

OBJECTIVE: To investigate 1) alterations of carotid intimal-plus-medial thickness (IMT) in subjects with IDDM and 2) the relation of IMT to indexes of diabetic angiopathy and to risk factors of atherosclerosis. RESEARCH DESIGN AND METHODS: IMT was assessed by ultrasound B-mode imaging in 39 subjects with IDDM (23 male, 16 female young adults aged 17.5 +/- 5.2 years, diabetes duration 8.8 +/- 5.9) and in 22 control subjects (healthy siblings of the IDDM subjects) of comparable age. Urinary endothelin (UET1) and urinary free cortisol (UFC) were determined by radioammunoassay (RIA), urinary albumin by nephelometry, HbA1c by high-performance liquid chromatography (HPLC), and plasma renin by immunoradiometric assay (IRMA). RESULTS: The IMT values were greater in IDDM subjects than in control subjects (0.49 +/- 0.1 mm, 0.44 +/- 0.09 mm, respectively; P = 0.048) and greater in IDDM male subjects than in control male subjects (0.52 +/- 0.09 and 0.44 +/- 0.06 mm, respectively; P = 0.015), with no difference between IDDM and control female subjects. The IMT values were greater in diabetic male subjects than in female subjects (0.52 +/- 0.09 and 0.45 +/- 0.1 mm, respectively; P = 0.017). In IDDM subjects, but not in control subjects, there was a positive correlation of IMT to urinary albumin (P = 0.008), systolic blood pressure (P = 0.023), UET1 (P = 0.016), UFC (P = 0.002), and BMI (P = 0.021). Multiple regression analysis demonstrated that in IDDM subjects the variable that interacts independently with IMT was the BMI (P = 0.001). CONCLUSIONS: IMT, an index of atherosclerosis (macroangiopathy), is increased in IDDM subjects quite early (already in adolescence), and it is positively related to urinary albumin, UET1, blood pressure, and UFC.